The last time I heard someone talk about the notorious “Generation Gap” was 1968 or maybe 1972, while I was arguing with my father about LBJ, or maybe it was Richard Nixon. (The mind is the first thing to go. Actually, it’s the second thing to go, after the hair.)
Back then, the phrase “generation gap” was in everyone’s vocabulary. If you had indigestion, it was because of the Generation Gap. High blood pressure or constipation? There’s no telling what body part the Generation Gap might strike.